1. Field of the Invention
One embodiment of the present invention relates to an object, a method, or a manufacturing method. The present invention relates to a process, a machine, manufacture, or a composition of matter. One embodiment of the present invention relates to a method for manufacturing a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, or an electronic device. In particular, one embodiment of the present invention relates to an electronic device and its operating system.
Note that electronic devices in this specification generally mean devices including secondary batteries, and electro-optical devices including secondary batteries, information terminal devices including secondary batteries, and the like are all electronic devices.
2. Description of the Related Art
Electronic devices carried around by users and electronic devices worn by users have been actively developed. For example, a thin portable electronic book is disclosed in Patent Document 1.
Such portable electronic devices and wearable electronic devices operate using secondary batteries as power sources. Portable electronic devices need to withstand the use for a long period and thus may incorporate high-capacity secondary batteries. Since high-capacity secondary batteries are large in size, their incorporation in electronic devices increases the weight of the electronic devices. Thus, small or thin high-capacity secondary batteries that can be incorporated in portable electronic devices are under development.
Patent Document 1 discloses a square lithium-ion secondary battery in which an active material mixture layer consists of a region with a plurality of openings and a region without openings and at least a bent portion of a collective sheet is covered with the region with the plurality of openings.